Combined wood and broken-stone pavement



A. AMBERG. GOMBINND WOOD AND BROKEN STONE PAVEMENT.l

Patented Jan. 8, 188.4.

(No Model.)

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WILLIAM A. Aivinnne, or cI-IIcAeo, ILLINOIS.

COMBINED WOOD ND` BROKEN-STONE PAVEMENT.

srEc'IrIcA'rIoN ferming part er'y Letters Patent Ne. 291,482, dated Jennery e, 1864. Applicationlfiled November 26, 1883. (No model.)

.To a/ZZ whom, it mag/concern,.-

Be it known` thatl, WILLIAM A. A'Mnnnc, residing at Chicago, inthe county of Cook and State of Illinois, and a citizen of the United States, have invented certain new and useful Improvements in Combined Wood and Broken-StonePavements, of which the following is a full description, reference being had tothe accompanying drawings, in which- Figure lrepresents a section of a portion of a street, taken crosswise; Fig-"2, a section taken lengthwise of a portionthe'reof; Fig. 3, a section similar to Fig. l, showing the improvements as applied to old, badly worn or decayed blocks; also showing the plank or board foundation. Fig. 4 shows the improvements applied to round blocks.

The object of this invention is to prevent the wear and decay of wooden blocks when it is applied to new pavements, and to prevent the further decay land level up the street surface when applied to old blocks,i to combine with one form of pavement certain advantages which another presents, and overcoming by such combination vcertain defects or undesirable features in each; and its nature consists in covering the wooden pavement with a layer 4or stratum'of granitic, porphyritic, or other stone sufficiently hard to be partly driven into or embedded in the wood, with a top 'dressing `of ner but otherwise smilar material to fill the interstices andpack and keep the material in place and prevent the working up ofthe stone. y u i In the drawings, A indicates the wooden blocks; B, the sand or earth foundation; C, the stratum or layer of larger broken hard stones; D, the stratum of more iinely broken or ground stone or the top dressing, and E a board or plank foundation.

The foundationB is usually prepared and brought to the proper contour with earth having a dressing of sand or other material, the whole thoroughlyr or sufficiently compacted to resist the pressure of the vehicles passing over the finished pavement, and I preferito lay the blocks directly upon this prepared, sand, earth, or other foundation, as withthis construction there is no springing of the blocks, as there is liable to be when aboard vor plank foundation is used; and in casecffany settling of the blocks, the surface of the street is easily leveled, so that with this construction ofthe pavement the settling of the blocks is not injurious. Vli ere the foundation is thoroughly prepared, boards or planks may be used, as shown at Fig. 3.

In making new pavements, y the omission of the board or plank foundation, for a further reason that they add to the diiiiculty of taking up the street for the purpose oi' laying and repairing pipes, &c.

Where, however. a street has been alreadyl paved with planks and my improvements are added for the purpose of covering,-I do not disturb the original foundation. rIhe blocks, Whether rectangular, circular, or irregular, are laid in the usual manner upon the founda tion, and the spaces between them, when used, are or Inay be filled in the usual manner with gravel,gravel cemented with tar, or other suitable material. I then place over the blocks a stratum of broken hard, stone-such as granite in its varieties, quartz,porphyry, traprock, or other very hard stone-preferably those which from their nature do not readily disintegrate. Limestone and stones of that quality are too soft, and, when broken, do not generally present such angles or edges as are proper toV be driven into the wood, nor do they have sufficient hardness for this purpose. I spread this material over the wooden blocks to the depth of two or more inches, and then roll it down with a roller sufficiently heavy to partly embed a portion of the stone in the upper ends of the blocks or between the same, it being understood that the blocks are laid with their fibers vertically. I have found for this purpose a twelve-ton roller to be sufficient in practice. When thelarger or coarser stones I recommend pacted,Ithen spread over this course or stratum a layer of fine broken or ground stone of similar material, quartz or syenite granite being preferred, and again subject it to rolling or other pressure, so as to thoroughly intermingle it with the coarser stratum and giving, a strong compact surface.

I find that the best results are obtained by thoroughly wetting the blocks bci-'ore rolling, as it softens the wood and facilitates embedding the stone, and, again,by wetting the iine material before and during the process of rolling, as it lls the interstices more readily and makes IOO it more cdiripact. By this method of covering ous to the feet of horses.

lthe blocks, water has sufficient access to them to keep them moist and prevent dry rot,while it so far excludes the atmosphere and effect of the sunasfto prevent the ordinary rotting which takes place when wood is exposed to alternations of air and water, or dry and wet, and the wood is sufficiently buried to prevent decay in new pavements, and to practically arrest decay in old ones. By this method of construction of pavements, l am able to level up streets covered by old wooden pavements, by applying a greater quantity of the material in old or decayed places where depressions exist, though such places should be rst filled and compacted to a level with the surrounding blocks, and in case of any sinkage or giving way of the blocks or foundation afterthe street is finished by my method the surface of the pavement is easily repaired and brought again to the proper level by simply filling the depression wpth the same material.

Among vother advantages of my pavement I mention the following: It mak es less noise than a broken stone pavement, owing to the deadening` effect of the wooden blocks. It has greater elasticity, andis, therefore, less inj uri- .lt provides the best wearing and cleanest natural material on the lsurface where the wear takes place. For a pavement of similar depth, this for many localitiesI is materially cheaper.

Granite or similar stone embedded in wooden blocks and top-dressed, as described, presents a perfectly even surface, relieves the blocks from the jar of vehicles, which causes their displacement and wear, and lessens the noise, absorbs water readily, therefore prevents dry rot in the wooden blocks, and does not in itself become muddy, as would be the case with softer stones.

Owing to the specific gravity of this hard material, the surface does not readily wash away during rains, or by the use of sprinklers, and it has a sufficient body in and of itself to greatly strengthen the pavement.

What I claim as new, and desire to secure by Letters Patent, is as follows:

1. A pavement consisting of a stratum of wooden blocks supported upon a suitable foundation, covered by a stratum of hard broken stone, and a surface stratum of hard nelybroken stone to compact and cover the same, substantially as specified.

2. The herein-described method of forming street-pavement, bylaying wooden blocks upon a suitable foundation, filling the spaces between them, placing over them a stratum of broken hard' stones, rolling the broken stones with sufficient pressure to partly embed them in the blocks, and to compact them together, and then placing over said stratum a covering ofthe same, but finer material, and compact ing the two upper courses or strata together by a second rolling, substantially as described.

3. The herein-describcd method of restoring worn orpartly-decayed woodenpavements, by filling the lower decayed or worn portions to the level of the sound blocks with broken hard stones, then applying a complete stratum of broken hard stones, heavily rolled to drive them into the blocks and compact them together, and then applying a covering stratum of finely-broken or pulverized hard stones and rerolling the same, substantially as speciiied.

WILLIAM A. AMBERG.

Witnesses:

MARIE L. PRICE, L. L. BOND. 

